Sourdough Chocolate Cake

The acidity of sourdough complements the chocolate nicely, the same way buttermilk does, and reacts with the baking soda to make it rise. It also tenderizes the crumb, so this recipe uses all purpose flour instead of cake flour. This recipe is a way to use old starter, which provides acidity but does not require active yeast activity.

Ingredients

60 g (4 tbs) (2 oz) butter
70 g (2.5 oz) unsweetened chocolate
60 g (4 tbs) (2 oz) butter
225 g (8 oz) (1 2/3 cup) all purpose flour
3 g (1/2 tsp) salt
7 g (1 tsp) baking soda
250 g (1 1/4 cup) sugar
115 g (2) eggs
4 g (1 tsp) vanilla extract
225 g (1 cup) (8 oz) sourdough starter
160 g (3/4 cup) milk

Steps

Melt the first amount of butter and the chocolate together. Cool to room temperature until it sets.
Sift together the flour, salt, and baking soda.
Preheat the oven to 325 °F. Grease a 9-inch square baking pan or two 8-inch round baking pans.
Combine the chocolate-butter mixture with the remaining butter and sugar. Cream together until light and fluffy, about 5 minutes.
Add the eggs one at a time and beat in, then add the vanilla extract. Continue to beat until fluffy, about 1 minute.
Add the sourdough starter. Stir gently until evenly mixed.
Add the flour mixture and milk to the butter mixture. Mix slowly until incorporated, then beat vigorously 30 seconds until completely blended.
Spread evenly in the baking pan(s). Bake 50 minutes for the 9-inch square baking pan or 40 minutes for two 8-inch round baking pans.
Cool in the pan on a wire rack 5 minutes, then turn out of the pan and allow to cool completely.

Fill and frost as desired.